1. Field of the Invention
This invention relates to a process for resin finishing textile (i.e., a woven or knit cloth) containing cellulosic fiber which lowers the loss of color fastness, discoloration, rise in free formaldehyde concentration and the like occurring during long storage before heat treatment in postcuring owing to unreacted resin decomposition and/or dye decomposition caused by the action of a reaction catalyst and which ensures high crease-resistant property and shrink resistance, minimal processing discoloration and cloth strength loss, excellent pleating property, minimal puckering and good feeling.
2. Description of the Background Art
Many resin finishing agents and finishing processes have been considered for imparting crease-resistant property and shrink resistance to textiles containing cellulosic fiber.
These processes typically use glyoxalic resin or other so-called cellulose-reactive resin finishing agents. Generally, however, an attempt to enhance crease-resistant property and shrink resistance by imparting a larger amount of such a resin causes various problems owing to the formaldehyde and the like contained in the resin. Specifically, it markedly increases finishing discoloration and loss of color fastness and also hardens the textile feeling and lowers the strength of the finished cloth. On the other hand, reducing the amount of resin imparted improves such properties as finishing discoloration and color fastness but results in insufficient crease-resistant property and shrink resistance. The practice has therefore been to conduct the finishing within the range that gives the optimum mix among the incompatible properties of processing discoloration and color fastness on the one hand and crease-resistant property, shrink resistance and cloth strength on the other.
Resin finishing in postcuring involves making garments from cloth imparted with the resin finishing agent and then heat treating the garment to react and set the resin. At the time of cutting and sewing, the imparted finishing agent has not yet been crosslinked so the textile can be easily pleated and exhibits good anti-puckering property. When the cloth is stored for a long period between the imparting of the resin and the heat treatment for crosslinking the resin, however, decomposition of unreacted resin and the action of the reaction catalyst may reduce the color fastness and increase discoloration and the amount of free formaldehyde.
Different types of reaction catalyst differ considerably in their effect on color fastness. For instance, the effect of an acidic catalyst on the color fastness of a reactive dye is particularly great. Many reactive dyes are used for dyeing knits in view of their superb leveling and coloring performance. When an acidic catalyst is used in the resin finishing of cloth dyed with a reactive dye, however, some of the dye is likely to decompose owing to the action of the acidic catalyst if the cloth is stored for a long period following the imparting of the resin finishing agent. On the other hand, while use of a neutral metallic salt catalyst does not cause the dye decomposition encountered with an acidic catalyst, the neutral metallic salt catalyst must be used in a large amount when a large amount of resin is used to secure high crease-resistant performance. The reactive dye is therefore apt to suffer finishing discoloration and/or nitrogen oxide discoloration.
An object of this invention is to provide a process for resin finishing textiles which eliminates the aforesaid drawbacks of the postcuring method, namely, the problems of loss of color fastness, discoloration owing to dye decomposition and formaldehyde increase by unreacted resin and residual reaction catalyst during long storage before heat treatment, and which simultaneously achieves high crease-resistant property, shrink resistance, good feeling, excellent pleating property, and anti-puckering property.